Current variable speed drives typically include a fixed sheave and a movable sheave which is coupled by splines to a drive shaft. This splined connection must be routinely maintained with a lubricant such as oil or grease. The translational movement of the parts requires seals to contain the lubricant along the splined interface. When the lubricant leaks through the seals the loss of lubricant causes premature spline wear. Further, leaking lubricant often contacts one or more V-belts causing premature belt wear.
Other variable speed fan drives utilize drive fingers in one of the sheaves and corresponding recesses in the other sheave to rotatably couple the fixed sheave to the movable sheave. The drive fingers have a wear member positioned between the drive finger and the recess.
Variable speed fan drives implementing either the lubricated splines or the wear members require maintenance and monitoring to ensure that the fixed sheave and the movable sheave properly engage one another or the drive shaft.